This occurs when the font file is corrupted or an incorrect version. Delete the file and download it again from a different source.
If you are missing this font, you can find it through various community repositories or official Autodesk support channels: Chinese font change to question mark - Autodesk hztxt.shx font download
Disclaimer: Always verify the licensing of font files. Hztxt.shx is generally considered freeware for CAD interoperability, but ensure you download from a source that respects original distribution rights. This occurs when the font file is corrupted